Base for revolving office-chairs.



A. D. PETTIBONE.

BASE FOR REVOLVING- OFFICE CHAIRS.

APBLLOATIQN FILED FEB. 10, 1911-.

Patented Jan. 2, 1912.

` A mentary bottom plan of the base, showing Ammin n.

comrarmor Berrow, omo, a conrozwrroa or omo.,

` rasa For. anvorvnic crezca-camas;

Specification of Letters Ffa-inrit, 1

[Application sled February 1o, 191i. serial no. 697,762.

To all whom 'it concern:

Be it known'that I, ARTHUR D. PE'r'rr- H v BONE, a citizen of the United States, resi-. x 4 dent of Cleveland, county of Cuyahoga, andv State of- Ohio, have invented a new and useful Im rovement in vBases for Revolving Oiiicehairs, of which4 the -following is a specification, the principle of the invention being herein explained and the best modein which I have contemplated applying that principle, so as todistmguish 1t from other inventions.

. `My invention relates to bases for revolving oiice chairs, its object being 'to provide a base economical 'in construction and efficient in its structure, and at the same time to impart thereto a 'finished exterior form. The said invention consists of means hereinafter fully described and particularly set forthin the claims. i

The annexed drawing and the following description set forth in detailcertain means embodying my invention, the disclosed means, however, constituting but one of various mechanical forms in which the principle of the invention may be applied.'

In said annexed-drawingz--Figure l is a perspective view of a chair base embodying my invention. Fig. 2 is a bottom plan of a chair base embodying my invention, with the `bottom plate removed. Fig. 3 isa fragthe bottom plate in position thereon. Fig. 4 is a Vertical axial section of the core and adjacent parts.

The invention as `illustrated, comprises' four main parts, namely, the central metal core A,- the laterally projecting legs B, the filler members C,- and the bottom plate D. The core A isprovided with the usual vertical central cylind'ricalbore a, which receives the usual vertically slidable and exteriorly threaded sleeve, (not shown,) which ordinarily receives the chair spindle of the usual construct-ion.` The upper end of the core is provided with a circular flange a', and the sides of the core are intersected by four equidistant dove-tail grooves a2 which also intersect the lower or bottom surface of the core, as shown in Fig. 2. The inner ends of surface ofthe core when the upper surfaces of the legs abut the under surface of thev flange at, as shown in Fig.y 4. The bottom iplate. D is of a diameter equal to that of the flange. at, and is secured against the lower .end of the core by means of screws d, Fig. 3, which are screwed into the legs B.

The lateral surfaces of the legs are formed with channels b adjacent to the tenons '6, as shown in Fig. 2. Each two opposing channels in adjacent legs, form a dove-tail groove, and each such groove receives-.ja filler-member C having its end shaped tocorrespond with the shape ofthe dove-tail .I

groove which receives it. he `transverse ,dimension of these filler members 1s such Ithat they' 'form a driving fit with their groove, and their height is made equal to the distance from the under surface of 'flange a to the upper surface-of plate D when the latter is secured in position. The outer contour ofthe filler members and the position of the channels are preferably made such that the said contour will correspond with the contour of the plate D and flange a.

When the legs, core and filler members are assembled it will be seen that the inner portion of the solid angle formed by each PETTIBONE, 0F CLEVELAND, OHIO, ASSIGNOB T0 THE'RL. MARBLE two adjacent legs, is completely lled up between the plate and flange, and that furthermore the filler-members act as braces to supplement the bracing function of the core itself. These braces by reason of their being attached to the legs as above described, are furthermore incapable of inadvertent or unpremeditated removal resulting from thel ordinary usage to which the chair, of which the base forms a part, is subjected. The resulting structure is, hence, one which retains its integrityand in which the liability of the legs working loose, is reduced to a mlnimum consistent with the degree of economy ofA manufacture whichis imposed by the commercial conditions surrounding and dominating themanufacture and sale of this class of goods.

Having fully described my invention,

what I claim and desire to secure by Letters PatentV isz- 1. In a base for revolving oiice chairs, the combination of a central metal core; legs secured to and projecting laterally from said core; separate ller members placed between and secured in the space formed by adjacent legs and extending from leg to leg, one end cent legs forming av dove-tail groove; and filler members seated in said grooves, whereby such members form irremovable lateral braces for the legs as well as coverings for 15 said core.

Signed by me, this 6th day of February,

ARTHUR D. PETTIBONE. Attested by- C. H. PARKER, JOHN E. LERCH. 

